Mosco de la Merced (Juan Valdez Valentino) is a Mexican Luchador or professional wrestler, best known for his time in Asistencia Asesoría y Administración (AAA) where he was a part of Los Vipers for many years. Before adopting the Mosco de la Merced ring name he worked for as Loco Valentino for over 10 years. He is a former holder of the Mexican National Tag Team Championship with Fuerza Guerrera and held the Mexican National Atómicos Championship four times with Histeria, Psicosis II and Maniaco. His name roughly translates to "Mosquito of Mercy". Professional wrestling career He began his wrestling career under the name Loco Valentino, son of the original Loco Valentino who also trained him for his professional wrestling career. Valentino wrestled for the Universal Wrestling Association in the early 1990s, where he defeated Semanarista to win the UWA World Lightweight Championship on September 22, 1994. Valentino would hold the championship until the UWA closed down in January 1995 when he had to vacate the championship. Asistencia Asesoría y Administración After the UWA closed Valentino began working for Asistencia Asesoría y Administración (AAA), one of Mexico's largest wrestling promotions. His first major show appearance was on June 13, 1997 at Triplemanía V-A when he teamed up with Los Hamponeslosing to the team k own as Los Cadetes del Espacio ("the Space Cadets" Discovery, Ludxor, Super Nova and Venum). Later in 1997 he teamed up with Picudo to compete in a tournament for the Mexican National Tag Team Championship, but were eliminated in the first round by Heavy Metal and Venum. At the 1997 Verano de Escandalo teamed up with Los Hampones once again, only to lose to a team composed mostly Los Cadetes (Discovery, Ludxor and Venum) with added the spectacular undercarder Flying. Los Vipers In August, 1997 Cibernético formed a "Super Rúdo" group called Los Vipers a group that included Abismo Negro, Maniaco, Histeria, Mosco de la Merced and Psicosis II. A few weeks after Los Vipers was born Histeria was replaced by a new Histeria. Mosco de la Merced left AAA not long after the formation of Los Vipers, leaving AAA a man short in the stable. Mosco also held the Mexican National Tag Team Championship with Fuerza Guerrera and his departure forced AAA to either vacate the championship or come up with an alternative plan. The solution was to give the Mosco de la Merced mask